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Background While periprosthetic fractures following total hip arthroplasty (THA) are a well-known phenomenon for orthopedic surgeons, fragility fractures following THA are also a significant, though less studied, concern. Furthermore, patients who have undergone THA have several additional risk factors for fragility fractures, including motor weakness, bone atrophy, and limping. The aims of this study were to evaluate the incidence of fragility fractures following THA and to clarify the characteristics of these fractures. Methods This study included 5678 primary THA procedures in 4589 female patients. This study evaluated body morphology data, disease type leading to THA, Japanese Orthopaedic Association hip score, range of motion of the hip joint, and medical history. Distal radius and patella fractures were defined as fragility fractures. Risk factors for fragility fractures after THA were calculated by comparing the fragility fracture group with the non-fracture group. Results Fifty-three fragility fractures were confirmed in 53 patients (distal radius fracture: 32 fractures in 32 patients, patella fracture: 21 fractures in 21 patients). In the univariate analysis, the following eight risk factors for fragility fractures were significantly different between the groups: height, weight, follow-up period, developmental dysplasia of the hip, primary osteoarthritis, abduction before THA, internal rotation before THA, and external rotation before THA. Medical histories were not significantly different between the groups. There was no difference in any study factor and in the time of occurrence between the radius fractures and patella fractures analyzed as fragility fractures. Conclusions This study revealed that there are significant preoperative factors of fragility fractures following THA. These factors will serve as useful data for THA treatment strategies, preoperative explanations, and future studies.

Performing total hip arthroplasty (THA) as early as possible is recommended for rapidly destructive coxarthrosis (RDC) as it causes pain that becomes progressively more severe. However, acetabular bone loss remains an issue in THA. Special devices, such as a Kerboull-type plate, may be used for acetabular bone defects, but the procedure is highly invasive and often the patients are elderly, further complicating matters. We retrospectively investigated the clinical and radiographic results of THA using conventional hydroxyapatite-coated cementless cup in RDC.A total of 32 patients (35 hips) with RDC were enrolled in the study with a minimum 10-year follow-up. All THAs were performed using conventional hydroxyapatite-coated cementless cup. All patients were evaluated clinically according to the Harris hip score (HHS). Acetabular bone deficiency was classified according to the American Academy of Orthopaedic Surgeons (AAOS) classification.Eleven hips (31%) were AAOS type III, and none were type IV. Total HHS significantly improved from 36.5 to 79.4 (p 0.01). Two cups exhibited loosening. The overall implant-associated survival rate after 10 years was 91.4%.Clinical results of THA using conventional cementless implants for patients with RDC were acceptable. Thus, THA using conventional cementless implant is an effective and safe surgery for patients with RDC, minimizing surgical stress.

Background Of late, periarticular analgesic injection (PAI) has become a common alternative treatment for pain following total hip arthroplasty (THA). However, the systemic effects of PAI containing corticosteroids in patients subjected to THA have not been investigated. This study evaluated the analgesic efficacy and systemic effects of PAI containing a corticosteroid in patients subjected to THA. Methods This single-center, retrospective cohort study enrolled patients undergoing unilateral, primary THA. A total of 197 patients (200 hips) were included in the final analyses, with 87 hips in the PAI group and 113 hips in the control group. Numeric Rating Scale (NRS) and laboratory data were assessed preoperatively and on postoperative days (POD) 1 and 7. Pearson’s correlation coefficients were obtained to assess the correlations between the D-dimer level on POD 7 and each outcome measure on POD 1. Results The postoperative white blood cell count (WBC) was significantly higher in the PAI group than in the control group. Postoperative NRS, creatine phosphokinase (CK), and C-reactive protein (CRP) levels were significantly lower in the PAI group. D-dimer levels were significantly lower in the PAI group on POD 7. Postoperative aspartate transaminase (AST), alanine aminotransferase, blood urea nitrogen, and creatinine levels were within reference ranges. D-dimer levels on POD 7 showed a significant negative correlation with WBC on POD 1 (r=-0.4652) and a significant positive correlation with the NRS score and AST, CK, CRP, and D-dimer levels on POD 1 (r = 0.1558, 0.2353, 0.2718, 0.3545, and 0.3359, respectively). Conclusions PAI containing a corticosteroid may be an effective treatment for pain and inflammation after THA, and it does not seem to cause drug-induced liver or kidney injury. Moreover, corticosteroid PAI can may accelerate early ambulation, which prevents the elevation of postoperative D-dimer levels, and may reduce the risk of deep venous thrombosis.

Highlights • Septic arthritis of the hip joint is relatively uncommon in adults. • Ag-HA implants have not been used in two-stage total hip arthroplasty. • Ag-HA implants may be used in two-staged total hip arthroplasty., Introduction Septic arthritis of the hip joint in adults is a rare and potentially devasting disease. To the best of our knowledge, there have been no reports of two-stage total hip arthroplasty (THA) for the treatment of septic arthritis of the hip joint with a cementless hip implant that has antibacterial properties. Presentation of case We present a case of two-stage THA with a thermal-sprayed silver oxide-containing hydroxyapatite coating (Ag-HA) implant to treat septic arthritis of the hip joint with hip osteoarthritis in an 80-year-old woman. There was no complication or recurrence at 28 months follow-up after 2nd-stage operation. Discussion Ag-HA implants were found to have antibacterial activity within the subcutaneous tissues and bone, osteoconductive properties, and no adverse reactions in vivo. Moreover, no adverse events due to silver were reported in a clinical or radiographic study. Conclusion To further reduce infection after two-staged THA for septic arthritis of the hip joint, antibacterial implants, such as an Ag-HA implant, may be used.

Highlights • A case of boutonniere deformity of the second toe caused by sumo wrestling. • Forced passive flexion exerted on an actively extended PIP joint is the likely cause. • Surgical repair of the extensor mechanism and temporary pinning were effective., Introduction Traumatic boutonniere deformities of the fingers are well documented unlike those of the lesser toes. With few existing reports on boutonniere deformities of the lesser toes, the related pathology and treatment guidelines remain unclear. Presentation of case We present a case of traumatic boutonniere deformity of the second toe caused by sumo wrestling in a 23-year-old man. A flexion deformity of the proximal interphalangeal joint and hyperextension of the distal interphalangeal joint of the right second toe were observed, including a torn central slip and plantarly displaced lateral bands during surgery. Surgical repair of the extensor mechanism and temporary pinning led to good clinical results. Discussion Acute traumatic boutonniere deformity of the interphalangeal joint of the lesser toe is very rare. The mechanism of boutonniere deformity in this case is thought to be due to forced passive flexion exerted on an actively extended PIP joint, which is similar to that seen in fingers. Conclusion We describe the pathophysiology of a case of boutonniere deformity of the lesser toe and suggest the effectiveness of surgical treatment.

Background: Of late, periarticular analgesic injection (PAI) has become a common alternative treatment for pain following total hip arthroplasty (THA). However, the systemic effects of PAI containing corticosteroids in patients subjected to THA have not been investigated. This study evaluated the analgesic efficacy and systemic effects of PAI containing a corticosteroid in patients subjected to THA. Methods: This single-center, retrospective cohort study enrolled patients undergoing unilateral, primary THA. A total of 197 patients (200 hips) were included in the final analyses, with 87 hips in the PAI group and 113 hips in the control group. Numeric Rating Scale (NRS) and laboratory data were assessed preoperatively and on postoperative days (POD) 1 and 7. Pearson’s correlation coefficients were obtained to assess the correlations between the D-dimer level on POD 7 and each outcome measure on POD 1. Results: The postoperative white blood cell count (WBC) was significantly higher in the PAI group than in the control group. Postoperative NRS, creatine phosphokinase (CK), and C-reactive protein (CRP) levels were significantly lower in the PAI group. D-dimer levels were significantly lower in the PAI group on POD 7. Postoperative aspartate transaminase (AST), alanine aminotransferase, blood urea nitrogen, and creatinine levels were within reference ranges. D-dimer levels on POD 7 showed a significant negative correlation with WBC on POD 1 (r=-0.4652) and a significant positive correlation with the NRS score and AST, CK, CRP, and D-dimer levels on POD 1 (r=0.1558, 0.2353, 0.2718, 0.3545, and 0.3359, respectively).Conclusions: PAI containing a corticosteroid may be an effective treatment for pain and inflammation after THA, and it does not seem to cause drug-induced liver or kidney injury. Moreover, corticosteroid PAI can reduce D-dimer levels, which are associated with deep venous thrombosis. Early ambulation may prevent the elevation of postoperative D-dimer levels, and PAI containing a corticosteroid may accelerate early ambulation and reduce the risk of deep venous thrombosis.

Distal trochanteric transfer (DTT) has been widely performed to treat developmental dysplasia of the hip or Perthes disease. Total hip arthroplasty (THA) following DTT in patients with hip osteoarthritis is one of the most challenging procedures for hip surgeons, because great care must be taken regarding anatomical abnormalities of the greater trochanter and the soft tissue attached to the greater trochanter. To the best of our knowledge, there are no reports on THA after DTT. We herein report two cases of patients who underwent THA post DTT using cementless components. After THA, both patients developed abduction temporary contraction because of leg length extension and gluteus medius hypertension. However, in both cases, the contraction was reversible within two months and the final clinical result was good. Therefore, THA can be considered an effective and safe choice for treating osteoarthritis after DTT.

Orthopedic complications can cause issues and severe disability in patients with dwarfism. Thus, these individuals frequently undergo total hip arthroplasty to mitigate decline in daily functioning. Although studies have reported on the difficulties of orthopedic surgery in patients with dwarfism, many do not clearly define dwarfism and have a short follow-up period. We aimed to retrospectively investigate the clinical and radiographic results of total hip arthroplasty for patients with dwarfism.A total of 68 hips of 49 patients with height140 cm and at least 10-year follow-up periods were enrolled. All patients had conventional cementless implants. All hips were evaluated using the Japanese Orthopaedic Association hip score.The main hip disease etiologies were primary hip osteoarthritis (58%) and secondary osteoarthritis due to developmental dysplasia (31%). Rheumatoid arthritis, rapidly destructive coxarthrosis, spondyloepiphyseal dysplasia, childhood infection, and femoral head aseptic necrosis were also causative pathologies. Hip scores significantly improved from 44 to 82 out of 100. Overall implant-associated survival rate after 10 years was 94.1%. Cup loosening was observed in 2 hips, and subsidence5 mm was observed in 9 hips. Presence of Crowe IV in hips was a significant risk factor for total hip arthroplasty in patients with dwarfism (p 0.05); leg lengthening had a weak but significant correlation (r = 0.253, p 0.05).Total hip arthroplasty using conventional cementless implants for patients with dwarfism shows good clinical and radiological outcomes and has a relatively low perioperative risk.

Background The silver oxide-containing hydroxyapatite-coated socket (KYOCERA, Osaka, Japan) is a cementless antibacterial implant that has both the osteoconductivity of the HA and the antibacterial activity of silver. The silver oxide-containing hydroxyapatite coating was shown to have good osteoconductivity and new bone formation in vitro and in vivo. However, the histological bone ongrowth of this implant has not been proven in a clinical study. Methods We analyzed bone ongrowth using two silver oxide-containing hydroxyapatite-coated sockets that were removed in revision total hip arthroplasty for recurrent dislocation. A histomorphometric analysis was performed using a scanning electron microscope (SEM) connected to a CCD camera and an elemental analysis was performed by energy-dispersive elemental spectrometry (EDS). Result A white structure thought to be osseous tissue was attached to the retrieved socket surface macroscopically, and histological bone ongrowth of the silver oxide-containing hydroxyapatite coating of the socket was confirmed by SEM. In addition, the presence of silver in the silver oxide-containing hydroxyapatite coating was confirmed in an elemental analysis by EDS. Conclusion Histologically, the silver oxide-containing hydroxyapatite-coated socket presented bone ongrowth in this clinical study.

Antibacterial silver with hydroxyapatite (Ag-HA) is a promising coating material for imparting antibacterial properties to implants. We previously reported that 3% (w/w) silver with HA (3% Ag-HA) has both antibacterial activity and osteoconductivity. In this study, we investigated the effects of Ag-HA on the in vitro osteoblast function and the in vivo anchorage strength and osteoconductivity of implants. Production of the osteoblast marker alkaline phosphatase, but not cytotoxicity, was observed in cells of the osteoblast cell line MC3T3-E1 cultured on the 3% Ag-HA-coated surface. These results were similar to those observed with silver-free HA coating. In contrast, a significant high level of cytotoxicity was observed when the cells were cultured on a 50% Ag-HA-coated surface. The anchorage strength of implants inserted into the femur of Sprague-Dawley (SD) rats was enhanced by coating the implants with 3% Ag-HA. On the 3% Ag-HA-coated surface, both metaphyseal and diaphyseal areas were largely covered with new bone and had adequate osteoconductivity. These results suggest that 3% Ag-HA, like conventional HA, promotes osteogenesis by supporting osteoblast viability and function and thereby contributes to sufficient anchorage strength of implants. Application of 3% Ag-HA, which combines the osteoconductivity of HA and the antibacterial activity of silver, to prosthetic joints will help prevent postoperative infections.

Biofilm-producing bacteria are the principal causes of infections associated with orthopaedic implants. We previously reported that silver-containing hydroxyapatite (Ag-HA) coatings exhibit high antibacterial activity against methicillin-resistantStaphylococcus aureus(MRSA). In the present study, we evaluated the effects of Ag-HA coating of implant surfaces on biofilm formation. Titanium disks (14-mm diameter, 1-mm thickness), one surface of which was coated with HA or 0.5%–3.0% Ag-HA with a thermal spraying technique, were used. In vitro, the disks were inoculated with an MRSA suspension containing4×105 CFU and incubated for 1-2 weeks. In vivo, MRSA-inoculated HA and 3% Ag-HA disks (8.8–10.0 × 108 CFU) were implanted subcutaneously on the back of rats for 1–7 days. All disks were subsequently stained with a biofilm dye and observed under a fluorescence microscope, and biofilm coverage rates (BCRs) were calculated. The BCRs on the Ag-HA coating were significantly lower than those on the HA coating at all time points in vitro (p<0.05). Similar results were observed in vivo (p<0.001) without argyria. Ag-HA coating reduced biofilm formation by MRSA in vitro and in vivo; therefore, Ag-HA coating might be effective for reducing implant-associated infections.

The direct anterior approach for total hip arthroplasty (THA) has generated increased interest recently. The purpose of this study was to compare the duration to failure and reasons for revision of primary THA performed elsewhere and subsequently revised at our institution after the direct anterior vs other nonanterior surgical approaches to the hip.All primary THAs performed elsewhere and referred to our institution for revision were divided into the direct anterior approach (30 cases) or nonanterior approach groups (100 cases, randomly selected from 453 cases) based on the original surgical approach. Because all primary direct anterior THAs were originally performed after 2004 to eliminate temporal bias, we identified a subset of the nonanterior group in which the primary THA was performed after 2004 (known as the recent nonanterior group, 100 cases, randomly selected from 169 available cases).The mean duration from primary to revision THA was 3.0 ± 2.7 years (direct anterior approach), 12.0 ± 8.8 years (nonanterior approach), and 3.6 ± 2.8 years (recent nonanterior), respectively. There was a significant difference in time to revision between the direct anterior and nonanterior approach groups (P.001). Aseptic loosening of the stem was significantly more frequent with the direct anterior approach group (9/30, 30.0%) when compared with the nonanterior group (8/100, 8.0%, P = .007) and the recent nonanterior group (7/100, 7.0%, P = .002).Revision of the femoral component for aseptic loosening is more commonly associated with the direct anterior approach in our referral practice.

大腸癌患者に肋骨転移とガス壊疽を合併した1例を経験したので報告する．症例は73歳男性，下行結腸癌に対して下行結腸切除術施行．術後経過良好で退院．退院して3週後に右側胸部痛を主訴に近医受診．炎症反応の上昇を認め精査目的に当院紹介．胸腹部CTで第8肋骨および周囲にガス像を認め，ガス壊疽疑われ当科紹介となる．同日，緊急手術（掻爬，開窓）施行．掻爬部，血液培養からはクロストリジウム属菌が検出され肋骨生検から大腸癌の転移も合併していたことが判明した．創部は開放創としてウェットドレッシングし徐々に肉芽が盛り上がり閉創した．非外傷性ガス壊疽を診療した際は腫瘍の合併を考慮する必要がある．また癌患者を診療する際は転移，感染の合併等も念頭に置く必要があると考えられた．

成人の滑膜性骨軟骨腫症は文献上数多くみられるが，日常遭遇することはまれで特に小児での報告例は少ない．今回小児に発生した膝関節滑膜性軟骨腫症の1例を経験したので報告する．症例は10歳男児．平成21年5月頃より特に誘因なく右膝関節痛，水腫認め当科受診．滑膜性軟骨腫症疑い関節鏡視下手術施行した．関節内の白色遊離体と表面に軟骨を形成していると思われた滑膜を摘出・切除した．症状は軽減し日常生活は可能となったが，深屈曲時の違和感あり．X線上遊離体の残存を認め，再度関節鏡視下手術行い，術後短期では症状は軽快している．病理組織では滑膜組織内に硝子軟骨を形成しており，一部石灰化を呈していたが骨化は明らかではなかった．11ヵ月後の現在再発なく経過観察中である．小児での本疾患発症例の報告は少なく，その機序についても不明な点が多いが，文献的考察を加え報告する．

小児橈骨骨幹端部骨折における徒手整復後再転位に影響を及ぼす因子について検討を行った．平成19年4月から平成22年3月までに当院で治療を行った15歳以下の小児橈骨骨幹端部骨折219例中，転位または10°以上の屈曲変形を認め，徒手整復を行い経過観察可能であった20例を対象とした．X線学的評価として，側面像で，橈骨骨軸と遠位骨片のなす角をangulation，橈骨径に対する骨片転位の割合をtranslationとして用いた．経過中に10°以上のangulation，または30％以上のtranslationを認めたものを再転位例とし，再転位あり群（11例）と再転位なし群（9例）を比較検討した．骨折型において2群間で有意差を認めた．完全骨折の場合多くが転位を伴っており，そのため解剖学的整復が得られにくく，場合によっては初期治療からK-wireによる手術加療を考慮すべきと考える．

【はじめに】下腿外傷後に発症する鉤爪趾（claw toe）は，比較的稀な合併症である．今回，足関節骨折後にclaw toeを来した症例を経験した．【症例】67歳女性．農作業中に転倒し，重機に左足関節部を轢かれて受傷．足関節内果骨折を認めた為，骨折に対し観血的骨接合術を施行．術後2週間外固定後，部分荷重より歩行を開始．術後4週で退院．しかし術後6週頃よりclaw toeが出現し，歩行障害を来した為，術後3.5ヶ月で手術を行った．術中長母趾屈筋腱の筋腱移行部のやや近位で強く癒着した瘢痕組織を認め，これを切除し腱剥離を行うと，足趾の変形が改善された．【考察】claw toeの原因は様々あるが，本症例では直達損傷による長母趾屈筋の癒着が原因と考えられた．長母趾屈筋は長趾屈筋に交叉枝を出し，全趾の屈曲に影響することが多い．そのため長母趾屈筋腱の癒着剥離のみで変形を矯正でき，良好な成績を得ることができた．

対象は2008年4月から2010年4月まで当院にて施行した初回THA中，術後2日目，7日目に下肢静脈エコーを施行し術後6日目にD-ダイマーを施行した185例．男性38例，女性147例．平均年齢65.0歳．基本的にメドマーを術直後から開始し低分子ヘパリンを硬膜外チューブ抜去後から開始した．DVTを22例（11.9％）に認めたが症候性のPEは認めなかった．統計学的に術後6日目D-ダイマーのカットオフ値10μg/mlはDVT検出に有効であった．また術後7日目に初めてDVTを発症した5例はすべて術後6日目D-ダイマーが10μg/ml以上であった．当院における術後DVT発生率は11.9％であり他の研究と比較して遜色はなかった．今後も致死性のPEを防ぐため注意深く予防と検査を進めていく必要がある．

日本において，診断群分類に基づく包括点数評価（以下DPC）を導入している病院は，増加している．DPCの特徴は，医療情報の標準化・透明性にあり，このツールで各病院間を解析し医療の質の向上を図ることが目的とされている．我々は，DPC導入直後と，DPC導入後3年経過時，平均年齢（才），診療報酬点数（点），平均在院日（日），術前待機期間（日），再入院の有無について調査した．結果として，DPC導入後3年経過時に，平均在院日数は50％に減少，術前待機期間は約30％に減少，診療報酬点数は70％に減少した．医療経済学的な面からDPCの効果ありと判断した．しかし点数設定の決定過程はブラックボックスにあり，専門医学会からの監視が必要で今後検討の余地がある．

【背景】骨癒合評価時期について臨床現場や論文で医師間の認識に相違を感じることがあり，骨癒合と判定するタイミングを調査することとした．【方法】1.長崎大学，関連病院および佐賀骨折治療研究会所属医師103名を対象に，大腿骨骨幹部骨折に対して髄内釘を試行したレントゲンを経時的に提示．仮骨出現時期，仮骨架橋構造形成期，骨癒合時期，抜釘可能時期および整形外科経験年数についてメールアンケートを実施した．2.アンケートに用いたレントゲンを画像ソフトで処理し仮骨部の濃度，面積を評価．【結果】1.回答43名，経験年数は平均13.6年．いずれの時期においても医師間による相違が見られ，経験年数による差は見られなかった．2.仮骨部の濃度，面積は仮骨増生が強い時期に最大となり徐々に低下を認めた．【考察】レントゲンによる骨癒合評価は主観的要素や撮影条件により左右され，また整形外科医と放射線科医でも差を生じるとの報告もあり今回の調査でその傾向が認められた．

Background Prosthetic joint infection is a serious complication of implant therapy. To prevent prosthetic joint infection, we previously reported the features of silver oxide–containing hydroxyapatite (Ag-HA), which was prepared by mixing silver (a metal with antimicrobial activity) with HA. In this study, we evaluated the potential issues of total hip arthroplasty (THA) with an Ag-HA–coated implant. Methods We prepared an implant for THA that was coated with Ag-HA. In this study, the implant contained silver at a maximum quantity of 2.9 mg/implant. In this prospective interventional study, we performed THA with this implant in 20 patients and investigated the effects of silver. Results Blood silver levels peaked at 2 weeks after THA and gradually decreased thereafter. The highest blood silver level recorded during the postoperative follow-up was 6.0 ng/mL, which was within the normal range. The Harris Hip Scores increased in all cases, and activities of daily living improved markedly after THA with Ag-HA–coated implants. Implant failure was absent on radiography. No adverse reaction to silver was noted, and argyria was not observed in any case. No patients have developed infection after surgery. Conclusion This is the first clinical study of Ag-HA–coated implants in THA. Our Ag-HA–coated implants markedly improved patients' activities of daily living without causing any adverse reactions attributable to silver in the human body. Ag-HA is expected to reduce postoperative infections and prevent decreased quality of life in patients undergoing prosthetic arthroplasty, thus leading to more favorable outcomes.

Antibacterial silver with hydroxyapatite (Ag-HA) is a promising coating material for imparting antibacterial properties to implants. We previously reported that 3% (w/w) silver with HA (3% Ag-HA) has both antibacterial activity and osteoconductivity. In this study, we investigated the effects of Ag-HA on the in vitro osteoblast function and the in vivo anchorage strength and osteoconductivity of implants. Production of the osteoblast marker alkaline phosphatase, but not cytotoxicity, was observed in cells of the osteoblast cell line MC3T3-E1 cultured on the 3% Ag-HA-coated surface. These results were similar to those observed with silver-free HA coating. In contrast, a significant high level of cytotoxicity was observed when the cells were cultured on a 50% Ag-HA-coated surface. The anchorage strength of implants inserted into the femur of Sprague-Dawley (SD) rats was enhanced by coating the implants with 3% Ag-HA. On the 3% Ag-HA-coated surface, both metaphyseal and diaphyseal areas were largely covered with new bone and had adequate osteoconductivity. These results suggest that 3% Ag-HA, like conventional HA, promotes osteogenesis by supporting osteoblast viability and function and thereby contributes to sufficient anchorage strength of implants. Application of 3% Ag-HA, which combines the osteoconductivity of HA and the antibacterial activity of silver, to prosthetic joints will help prevent postoperative infections.

To reduce the incidence of implant-associated infection, we previously developed a novel coating technology using hydroxyapatite (HA) containing silver (Ag). This study examinedin vivoacute and subacute toxicity associated with the Ag-HA coating in rat tibiae. Ten-week-old rats received implantation of HA-, 2% Ag-HA-, or 50% Ag-HA-coated titanium rods. Concentrations of silver in serum, brain, liver, kidneys, and spleen were measured in the acute phase (2–4 days after treatment) and subacute phase (4–12 weeks after treatment). Biochemical and histological examinations of those organs were also performed. Mean serum silver concentration peaked in the acute phase and then gradually decreased. Mean silver concentrations in all examined organs from the 2% Ag-HA coating groups showed no significant differences compared with the HA coating group. No significant differences in mean levels of glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, lactate dehydrogenase, creatinine, or blood urea nitrogen were seen between the three groups and controls. Histological examinations of all organs revealed no abnormal pathologic findings. No acute or subacute toxicity was seenin vivofor 2% Ag-HA coating or HA coating. Ag-HA coatings on implants may represent biologically safe antibacterial biomaterials and may be of value for reducing surgical-site infections related to implantation.

An analytical method using GC/MS was developed for the determination of 11 alkylphenols and 2, 4-dichlorophenol (2, 4-DCP) residues in various foods. The phenolic compounds were extracted with 50% diethyl ether-hexane after the alkaline decomposition of food samples. The extracts were cleaned up on an acidic alumina column and a SAX cartridge. The phenolic compounds were derivatived with heptafluorobutyric anhydride and the derivatives or parent compounds were determined by GC/MS (SIM or SCAN). The method was applied to determine alkylphenols and 2, 4-DCP residues in 190 food samples purchased from markets. 4-Nonylphenol was found in some fish, meat and vegetables at the levels of 10-723ng/g, 9-180ng/g and 7-131ng/g, respectively. In addition, 2, 4-DCP was detected in some vegetables (2-17ng/g).

A method for determination of maleic hydrazide in agricultural products by gas chromatography was developed. Maleic hydrazide was extracted by reflux in hydrochloric acid solution. The extract was reacted with dimethyl sulfate under an alkaline condition to form the dimethyl derivative, which was extracted twice with ethyl acetate. After deactivated Florisil column chromatography, the derivative was determined by gas chromatography using a nitrogen-phosphorus detector and gas chromatography-mass spectrometry.The recovery of maleic hydrazide added to agricultural products at 1ppm was 72.0-98.2%. The detection limit of maleic hydrazide was 0.5ppm.

Water and sediment samples in a bay surrounded by heavily industrialized areas were analyzed by a combined gas chromatography/mass spectrometry/computer system, and a number of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), and polar oxygenated compounds were found. Behavior of PAH in the bay and its surroundings was traced by gas chromatographic fingerprint by using a glass capillary column. Water and sediment, dust fall, and airborne particulate samples were used as environmental samples. It was emphatically suggested that the major origin of sedimentary PAH was airborne dust.

縮合リン酸塩類の摂取原因となる食品を明らかにするために, まず分析法を迅速簡易化した。すなわち均質化した試料5.00gを遠心管に秤り入れ, あらかじめ氷冷した10%トリクロロ酢酸35mlを加えて3分間振とう抽出した。必要に応じて遠心分離を行い, 上清を綿栓ろ過してろ液を50ml容メスフラスコに集めた。1試料につき2本のイオン交換樹脂カラムを用いて, リン酸塩類の定性試験と分画を行った。オルトリン酸 (OP) は, モリブデン錯体として酢酸ブチルで抽出し, 310nmの吸光度を測定して定量した。各縮合リン酸塩 (CP) 分画は, 加水分解後, 発色させ830nmの吸光度を測定して定量した。OPは, 全試料から検出された。各種のCPが, いも類豆類加工品, 肉類・魚介類加工品, 油脂類・乳類加工品およびその他の加工食品等から検出され, これらの食品がCPのおもな摂取原因食品であると推定された。